In delivery of enzyme/substrate systems, two problems generally arise. The first problem is that optimal effectiveness depends on maintaining the proper enzyme:substrate ratio. The second problem is that enzyme must be physically isolated from its substrate until the reaction is desired. One way to overcome these problems is to package enzyme separately from substrate and combine them at the point of use. However, this approach is inconvenient, complicated, and can result in blending errors at the point of use. It can also be costly since the enzyme often must be formulated with stabilizing substances. Another way to overcome these problems is to provide a blend of dry enzyme and dry substrate, thus achieving physical isolation while maintaining the proper enzyme-to-substrate ratio. However, it is frequently desirable or necessary to provide a liquid formulation for use in processes which are not set up to handle powders, granules, or other solid products. An alternative approach is needed.
A co-formulation approach would be desirable, with enzyme and substrate combined in the same container. This would allow a manufacturer to control the enzyme:substrate ratio, resulting in cost savings on formulation ingredients, and would provide a simple, convenient, and “ready-to-use” product to the consumer. In some cases, combining enzyme and substrate in the same liquid formulation could mitigate toxicity concerns (e.g., environmental risks posed by laccase mediators could be substantially reduced if they could be handled and transported in the same container as the laccase enzyme itself).
Ounichi (U.S. Pat. No. 4,898,781) and Aronson (U.S. Pat. No. 5,281,355) teach encapsulation of enzymes for laundry and home care applications where the resulting product contains only an enzyme, and does not contain a reactive substrate. It would be desirable to produce a liquid formulation containing both enzyme and substrate, with the enzyme isolated from the reactive substrate. Applications in which such a co-formulation would be useful include, but are not limited to, enzymatic bleaching systems, for example, using a perhydrolase enzyme with an ester substrate, and enzymatic dyeing systems, for example, using a laccase enzyme and a dye precursor substrate.